The purpose of this project is to produce some monodisperse anomalous polymer microspheres having high light scattering ability and we have succeeded it as follows:1. Anomalous polymer microspheres having many voids therein were produced by two steps alkali/acid treatment, which we proposed, of styrene-butyl acrylate-methacrylic acid terpolymer microspheres prepared by emulsifier-free emulsion terpolymerization.2. Anomalous polymer microspheres having uneven surfaces were produced by stepwise heterocoagulation method, which we proposed. For example, 0.2 um-sized cationic polymer particles having Tg of about 100ﾟC were coagulated onto 0.8 mu-sized anionic polymer particles having Tg of about 70ﾟC. The surface unevenness of the heterocoagulated particles could be controlled by heat treatment.3. "Golf ball-like" polymer particles were produced by seeded emulsion polymerization of butyl acrylate in the presence of polystyrene particles.4. Micron-sized polymer particles having voids therein were produced by extraction treatment of crosslinked monodisperse polymer particles with toluene under reflex, which were produced by seeded copolymerization for monomer-swollen particles of polystyrene with styrene and divinyl benzene prepared by the dynamic swelling method, which we produced.We have confirmed that a part of the above produced particle had a high light scattering ability.